.site {
    width: 300px;
    height: 600px;
    background: red;
    margin: auto;
}

.box {
    width: 150px;
    height: 50px;
    margin-top: 10px;
    position: relative;
    top: 300px;
    left: 75px;
}

.box1 {
    animation: mymove 1s ease 0.1s;
    animation-fill-mode: forwards;
}

.box2 {
    animation: mymove 1s ease 0.2s;
    animation-fill-mode: forwards;
}

.box3 {
    animation: mymove 1s ease 0.3s;
    animation-fill-mode: forwards;
}

.box4 {
    animation: mymove 1s ease 0.4s;
    animation-fill-mode: forwards;
}

@keyframes mymove {
    from {
      left: 375px;
    }
    to {
      left: 75px;
      background: blue;
    }
  }
  